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Abstract:

The disclosed technology relates to nanotechnology, petrochemistry, gas
chemistry, coal chemistry, in particular to a catalyst based on carbon
nanotubes for synthesis of hydrocarbons from CO and H2 and a
preparation method thereof. The carbon nanotubes fixed in the catalyst
pellet pores improve mass and heat transfer in the catalyst pellet and
the catalyst bed.

Claims:

1. A catalyst for synthesis of hydrocarbons from CO and H2
comprising a metal from Group VIII of the Mendeleev's Periodic Table of
the Elements as an active component and a porous support with an oxide
component, wherein carbon nanotubes are grafted into the pore walls of
the support.

2. The catalyst according to claim 1, wherein the active component is a
metal selected from the group consisting of Co, Fe and Ru and the metal
content is 10-45% by weight based on the total weight of the catalyst.

3. The catalyst according to claim 1, wherein the oxide component is
selected from the group consisting of oxides of aluminium, silicon,
titanium, zirconium, magnesium, lanthanum, zeolites, mixed oxides and/or
mixtures thereof.

4. The catalyst according to claim 1, wherein the support pore size is at
least 10 nm.

5. The catalyst according to claim 1, wherein the porous support content
is 45-80% by weight based on the total weight of the catalyst.

6. The catalyst according to claim 1, wherein the carbon nanotube content
is 10-35% by weight based on the total weight of the catalyst.

7. The catalyst according to claim 1, wherein the catalyst further
comprises promoters that are elements of Groups II-IV and/or VI-VIII of
the Mendeleev's Periodic Table of the Elements, wherein the promoter
content is 0.1-5% by weight based on the total weight of the catalyst.

8. A method for preparing a catalyst for synthesis of hydrocarbons from
CO and H2 comprising a metal from Group VIII of the Mendeleev's
Periodic Table of the Elements as active component and a porous support
with an oxide component, wherein the method comprises: applying the
active component onto the oxide component by impregnation with an aqueous
solution of the metal salt, drying, calcinating, treating in hydrogen
stream to obtain a porous material, wherein the carbon nanotubes are
deposited and grafted by flowing carbon-containing gas through the porous
material at 600-650.degree. C., treating repeatedly with a solution of a
salt of a metal selected from the group consisting of Co, Fe and Ru until
the metal content of 10-45% by weight based on the total weight of the
catalyst has been achieved, drying, and calcinating.

9. The method according to claim 8 wherein the active component is a
metal selected from the group consisting of Co, Fe and Ru and the metal
content is 10-45% by weight based on the total weight of the catalyst.

10. The method according to claim 8, wherein the oxide component is
selected from the group consisting of oxides of aluminium, silicon,
titanium, zirconium, magnesium, lanthanum, zeolites, mixed oxides and
mixtures thereof.

11. The method according to claim 8, wherein the carbon nanotube content
is 10-35% by weight based on the total weight of the catalyst.

12. The method according to claim 8, further comprising impregnating the
support is with a solution of a salt of a promoter that is a metal of
Group II-IV and/or VI-VIII of the Mendeleev's Periodic Table of the
Elements and/or an oxide thereof, wherein the promoter content is 0.1-5%
by weight based on the total weight of the catalyst.

Description:

FIELD OF THE INVENTION

[0001] The present invention is about nanotechnology, petrochemistry, gas
chemistry, coal chemistry and it relates to a catalyst composition for
exothermic processes, particularly for synthesis of C5 and higher
hydrocarbons from CO and H2 under the Fischer-Tropsch reaction and a
preparation method thereof.

BACKGROUND OF THE INVENTION

[0002] The production of hydrocarbons from carbon monoxide and hydrogen
(the Fischer-Tropsch process) is carried out in the presence of catalysts
based on metals selected from the Group VIII of the Mendeleev's Periodic
Table of the Elements. The catalyst composition plays a key role in the
production of hydrocarbons because it gives a final result, i.e. product
composition.

[0003] It is well-known that the production of hydrocarbons from CO
H2 is exothermic and is carried out at high pressures. There is a
need in improvement of the catalyst composition to maintain high activity
and selectivity of catalysts. Such improvement will give an option
cutting the likelihood of local overheating which has an adverse effect
on catalyst selectivity for production of the main products and causes
the catalyst deterioration.

[0004] The main requirements for the catalytic bed formation in the
Fischer-Tropsch process (e.g. high concentration of catalytically active
component in the reaction volume, small size of the catalyst particles
(less than 50 μm); high heat conductivity of the catalyst bed; the
extended surface of the gas-liquid interphase; providing regimen of the
gas convection current close to plug flow) are not fulfilled in the
current process flow diagrams where the usual catalysts in slurry, fixed
or fluidized bed are used (Hasin A. A. et al., Catalysis in industry, No
2, 2002, p. 26-37). Therefore the effective production of hydrocarbons
from synthesis gas requires development of the new type catalysts.

[0005] The above- described problem takes place in the process on a solid
catalyst (pelletized, ring-shaped and the like) which forms the fixed bed
and is placed inside the tube divided the gas space with the catalyst and
the liquid phase (water) for heat removal. One of the methods for
overcoming the process problem is increasing of the heat conductivity of
the solid catalyst. It is possible to increase the heat conductivity of
the solid catalyst by using of metals, carbides and nanocarbon material
as catalyst components (S. Berber et al., Unusually High Thermal
Conductivity of Carbon Nanotubes, Physical review letters, Vol. 84, N.
20, 2000, p. 4613-4616).

[0006] WO2004069407 discloses a preparation method of a catalyst for
production hydrocarbons and/or oxygen-containing compounds from synthesis
gas. The catalyst is prepared from powders of a catalytically active
agent, a heat-conducting agent and a pore-forming agent with particle
size less than 300 μm. Firstly the powders of the heat-conducting and
pore-forming agents are mixed, then the powder of the catalytically
active agent is added to the mixture, the mixture is compressed, the
catalyst body is putted into the required shape and the heat treatment of
the catalyst body takes place. The compressing and shaping the catalyst
body into cylinder or perforated cylinder or plate or profiled plate is
carried out by pelletizing in a rolling mill; the blanking of the plate
of the required form is added. The heat treatment is two-stage, firstly
in the inert gas current at temperature above 400° C. and then in
the hydrogen-containing gas current at temperature above 300° C.
The catalytically active agent comprises a metal selected from the Group
VIII of the Mendeleev's Periodic Table of the Elements in amount of at
least 2 wt %. The metallic copper and/or zinc and/or aluminium and/or tin
and/or mixtures or alloys thereof are used as the heat-conducting agent.
An oxide and/or hydroxide and/or carbonate and/or hydroxocarbonate and/or
a salt of the metal from the heat-conducting agent or the powder of the
catalytically active agent are used as the pore-forming agent. The weight
content of the pore-forming agent to the weight content of the
heat-conducting agent ratio is 0.25-4. The disadvantage of the catalyst
is a disalignment of the catalyst body position and the direction of the
reaction stream. Therefore in spite of the heat-conducting agent presence
such catalyst has low efficiency (CO conversion does not exceed 15% at
syngas hour space rate 930 1/h).

[0007] EP0681868 relates to a catalyst for the Fischer-Tropsch process.
There is cobalt or iron loaded on a support in the catalyst. The support
is carbon with the specific surface area at least 100 m2/g. The
catalyst comprises a promoter--platinum (0.2-10% ). The catalyst is
prepared by impregnation of a carbon powder (0.5-1.0 mm) with an aqueous
solution of metal salts. Previously carbon from the organic material
(such as coconut coal, peat, coal, carbonized polymers) is treated
subsequently at a temperature of 300-3300° C. in an inert,
oxidizing and again in inert atmosphere. The production is carried out at
a temperature 150-300° C., pressure 0.1-5 MPa and H2:CO ratio
of 1:1-3:1. The drawback of the catalyst is low selectivity of C5
and higher products due to the quite low heat conductivity of the
support.

[0008] SU1819158 provides a catalyst for production of hydrocarbons from
synthesis gas. The catalyst comprises iron as active component, copper,
silicon, potassium and coal (2-20 g on 100 g of iron) activated with
steam or mineral acid. The catalyst is obtained by individual dissolving
iron and copper in nitric acid at elevated temperature, then they are
mixed and the obtained solution is brought to the boil, alkali liquor or
calcined soda solution is added to the boiled suspension to adjust pH to
7-8. The suspension is filtered, the solids are suspended in a steam
condensate and potassium containing waterglass is added, followed by
nitric acid treatment, the catalyst precipitate separation, drying and
formation by extrusion, additional drying and desintegration. The
Fischer-Tropsch synthesis is carried out in a reactor with a fixed bed of
the catalyst under a pressure 20-30 bar and a temperature 220-320°
C. The yield of the solid product in the form of wax is 40-55% on
hydrocarbons C2+ basis. The drawbacks of the catalyst are low
productivity and selectivity for the main products, as well as a quite
difficult preparation method.

[0010] Carbon nanofiber is a material consisting of thin threads, formed
mainly by carbon atoms, each thread less than 1 μm in diameter. Carbon
atoms are united into microcrystals, aligned in parallel each other.
Carbon fibers are characterized by high tensile strength and chemical
resistance, low specific density and coefficient of thermal expansion.
Some carbon fibers have higher heat-conductivity along the fiber axis.
Carbon nanotube (SWNT, MWNT) is one of the forms of the carbon nanofiber
and has maximum heat conductivity. The microstructure of carbon nanotubes
differs from the structure of other carbon nanofibers by extended
cylindrical structures. These structures have a diameter from one to
several dozens nm and they are usually up to few μm in length.

[0011] An ideal nanotube is a graphite layer rolled up into a hollow
cylinder; the graphite layer is composed of hexagons and every vertex of
such hexagon is the carbon atom. However the structure of the
experimental single-wall carbon nanotubes is not ideal in many ways.
Multiwall nanotubes differ from the single-wall nanotubes by a wide range
of shapes and configurations. There are different structures both in the
longitudinal and transverse directions. Multi-wall carbon nanotube
structure formation depends on synthesis conditions in the specific
experiment. An analysis of experimental data demonstrated that the most
typical structure of the multi-wall carbon nanotube is a structure like a
Russian doll in which tubes of smaller diameter are coaxially arranged
within tubes of bigger diameter.

[0012] Carbon nanotubes were first synthesized by evaporation of graphite
in the arc discharge. In accordance with the present invention carbon
nanotubes are formed by chemical vapor deposition (CVD). During CVD, a
substrate is prepared with a layer of metal catalyst particles (most
commonly nickel, cobalt, iron, or a combination thereof). The substrate
is heated to approximately 600-1200° C. To initiate the growth of
nanotubes, a carbon-containing gas (such as acetylene, ethylene, ethanol
or methane etc.) is bled into the reactor. Nanotubes begin to grow at the
sites of the metal catalyst.

[0013] Therefore it will be attractive to use carbon nanofiber and
nanotubes in the catalyst composition; it makes possible to increase the
heat conductivity of the catalyst and have a good influence on the
catalyst efficiency.

[0014] However the catalysts comprising carbon nanofibers or nanotubes
have disadvantages. Particularly carbon nanofibers and nanotubes are
corrodible because of hydrogenation. Should the arrangement of carbon
nanofibers and nanotubes in the catalyst provides contact of the
nanomaterial mainly with hydrogen-containing gas rather than main
products, the disadvantage may come out. Although carbon nanofibers and
nanotubes have high heat conductivity, they are not able to transfer full
heat flow to the surrounding particles by reason of low contact heat
conductivity (in the event of free arrangement). It leads to the second
disadvantage. Moreover active components of the catalyst have low
activity, if the major part of the surface (for loading of the active
components) is carbon that is not mixed and impregnated with other
components, e.g. oxide components.

[0016] The main drawback of the catalyst is low activity because the
active centers of the catalyst are loaded directly into nanocarbon
arranged in the catalyst in such way that the nanomaterial contacts
mainly with hydrogen-containing gas. Also a loss of the catalyst in the
hydrogenation process of the nanocarbon coating is significant.

[0017] EP1782885 discloses a carbon nanotubes supported cobalt catalyst
for converting synthesis gas into hydrocarbons. The catalyst is prepared
by incorporating cobalt and/or ruthenium and optionally an alkali metal
onto a CNT support. The catalyst is suited for the conversion of
synthesis gas into a mixture of essentially linear and saturated
hydrocarbons. The cobalt content, expressed by weight % of cobalt based
on the total weight of the catalyst is between 1 and 60% , the ruthenium
content, expressed by weight % of ruthenium based on the amount of cobalt
present in the catalyst, is between 0.1 to 1% and the alkali metal
content, expressed weight % of alkali metal based on the amount cobalt
present in the catalyst, is between 0 to 3% by weight.

[0018] The main drawback of the catalyst is an absence of the possibility
to use the catalyst in industrial conditions. High yield of the product
may be achieved only at low syngas load because the heat released during
the process may be removed from the active centers and nanotubes together
with the products. The purpose of using CNT in the catalyst is limited by
obtaining of the dispersed cobalt clusters.

[0019] RU2325226 provides a catalyst for synthesis of hydrocarbons from CO
and H2 comprising a metal of the VIII group of the Mendeleev's
Periodic Table of the Elements and a support, comprising an oxide
component and carbon nanofiber. The active component content is 5-40% by
weight based on the total weight of the catalyst and the oxide component
contains aluminium oxide and/or silicon oxide and/or titanium oxide
and/or zirconium oxide. Additionally the catalyst can include promoters
(zirconium and a metal of the VII, VIII groups of the Mendeleev's
Periodic Table of the Elements and/or oxides in an amount of 0.1-5% by
weight based on the total weight of the catalyst). As well as the
catalyst contains carbon nanofiber in form of cylinders of about 3 mm in
length and at least 20 μm in diameter in an amount of 1-25% by weight
based on the total weight of the catalyst. The method of making the
catalyst comprises preparation of the paste which consists of oxide
component, carbon nanofiber, boehmite as binder, water, a plasticizer,
and a pore-forming component; followed by extrusion, drying, calcinating,
and then the consecutive stages of the impregnation with a solution of
metal salts are carried out until the content 5-40 wt % of cobalt and
0.1-5% of promoters have been achieved. After each stage of the
impregnation the drying and calcinating are performed.

[0020] Before carrying out the synthesis, a sample of the catalyst is
activated by reduction in the stream of hydrogen (gas hour space rate
100-5000 1/h) at a temperature in the range from 300 to 600° C.
during a time period from 0.5 to 5 hours. Synthesis of hydrocarbons from
CO:H2 is carried out in a tubular reactor with a fixed bed of the
catalyst under a pressure in the range from 0.1 to 4 MPa and a
temperature in the range from 150 to 300° C.

[0021] However the active component is applied to the support by
impregnation, the support comprises the oxide component and metallic
aluminium as heat-conducting component. Such procedure results in
overconsumption of the expensive active metal to provide the claimed
activity and selectivity of the catalyst.

[0022] Chin et al. report (Chin Y. H. et.al., Preparation of a novel
structured catalyst based on aligned carbon nanotube arrays for a
microchannel Fischer-Tropsch synthesis reactor, Catalysis Today, v. 110,
pp. 47-52, 2005) a microstructured flat catalyst based on aligned
multiwall carbon nanotube arrays for Fischer-Tropsch synthesis in a
microchannel reactor. The carbon nanotube arrays are disposed on the
surface of metalloceramic alloy foam. Also Chin et al. report the
preparation of such catalyst comprising few difficult and time-consuming
stages. Preparation method of the structured catalyst with the carbon
nanotubes on the surface of the metalloceramic alloy foam involves the
following stages:

[0023] 1) the FeCrAlY intermetallic alloy foam is prepared;

[0024] 2) the FeCrAlY intermetallic foam is oxidized in air; and then
coated with a layer of aluminium oxide by the metal organic chemical
vapor deposition (MOCVD) of aluminum isopropoxide at 900° C.;

[0025] 3) the Fe/mesoporous silica sol is prepared and coated onto the
foam;

[0026] 4) the obtained material is dried and calcinated;

[0027] 5) the carbon nanotube growth is carried out by catalytic
decomposition of ethylene at 700° C.

[0028] 6) the material with carbon nanotubes is subsequently dip coated
with a colloid alumina alcoholic solution, then an aqueous solution
containing cobalt nitrate and pherrennic acid to apply
Co--Re/Al2O3 onto the material;

[0029] 7) after each dip drying and calcining at 350° C. for 3 h in
air is repeated;

[0030] 8) the catalyst is activated (or reduced);

[0031] 9) the catalyst is tested in a microchannel steel reactor.

[0032] The carbon nanotubes are fixed on the metalloceramic substrate that
provides the efficient heat transfer from the active centers (disposed on
the free ends of the nanotubes). However the direction of the heat
removal does not correlate anyway with the directions of the reagent and
product flows. This fact inevitably negates the efficiency of the heat
removal in the reactor. The carbon nanotubes stay out of the mass
transfer because the reagents and products are flowed from the free ends
of the nanotubes to the outside. It is impossible to use such catalyst in
the usual catalytic reactor; this view is substantiated by the author's
recommendation to use the catalyst in the microchannel reactor. The
stated disadvantages are compensated for the performance features in the
microchannel system.

[0033] The catalyst has other drawbacks. The catalyst has the
sophisticated structural design. The preparation method is quite
complicated; it results in quite low technical parameters of the
catalyst, namely CO conversion of 42% and CH4 selectivity of 27% .
Also that multistage and labor-intensive preparation method makes
impossible use of the catalyst in industry.

[0034] Therefore the catalysts and the preparation methods described above
have the following principal drawbacks: high cost due to high content of
the expensive components; low heat conductivity of pellets; complexity of
preparation and need of high temperature processing, which require
special equipment, increase the catalyst cost and overcomplicates the
preparation method.

[0035] Numerous studies of the inventors demonstrate that using nanotubes
and nanofibers would be efficient if their arrangement in the catalyst
gives possibility to enhance the heat flow from the active centers of the
catalyst in the direction of the reagent and product flows. Mass transfer
intensification would be possible in result of high affinity of the
produced hydrocarbons and the graphite-like surface of the carbon
nanotubes. The carbon nanotubes have to meet the following criteria to
achieve the required effect: firstly almost an ideal cylindrical
structure but with enough defects for the intermediate
sorption/desorption of hydrocarbons; secondly a length comparable with a
path length of a molecule of the product from the active center to the
catalyst pellet surface; thirdly, an arrangement along the withdrawal
path of the product from the active centers to the catalyst pellet
surface, preferably along the walls of the transport pores.

[0036] Summarizing the aforesaid it should to be noted that a need exists
for an effective, selective catalyst of new type, such catalyst should be
stable to overheating, reliable, with improved heat- and mass-transfer in
the catalyst pellet and in the catalyst bed as a whole, low-cost along
with high activity. As well as there is a need in a simple and safe
preparation method of the catalyst.

SUMMARY OF THE INVENTION

[0037] In accordance with the present invention a catalyst for synthesis
of hydrocarbons from CO and H2 is provided. The catalyst comprises a
metal selected from Group VIII of the Mendeleev's Periodic Table of the
Elements as active component and a porous support with an oxide component
wherein carbon nanotubes are grafted to the pore walls of the support.

[0038] In one preferred embodiment of the invention the active component
is a metal selected from Co, Fe or Ru and the metal content is 10-45% by
weight based on the total weight of the catalyst.

[0039] In one preferred embodiment of the invention the oxide component is
selected from oxides of aluminium, silicon, titanium, zirconium,
magnesium or lanthanum, zeolites, mixed oxides and/or mixtures thereof.

[0040] In one preferred embodiment of the invention the support pore size
is at least 10 nm.

[0041] In one preferred embodiment of the invention the porous support
content is 45-80% by weight based on the total weight of the catalyst.

[0042] In one preferred embodiment of the invention the carbon nanotube
content is 10-35% by weight based on the total weight of the catalyst.

[0043] In one preferred embodiment of the invention the catalyst further
comprises promoters, moreover the elements of II-IV and/or VI-VIII groups
of the Mendeleev's Periodic Table of the Elements are used as the
promoters and the promoter content is 0.1-5% by weight based on the total
weight of the catalyst.

[0044] The present invention also relates to a method for preparing a
catalyst for synthesis of hydrocarbons from CO and H2 comprising a
metal selected from the Group VIII of the Mendeleev's Periodic Table of
the Elements as active component and a porous support with an oxide
component, the method comprises: the active component is applied onto the
oxide component by impregnation with an aqueous solution of the metal
salt; followed by drying, calcinating and treatment in hydrogen stream to
obtain the porous material, the carbon nanotubes are deposited and
grafted by flowing carbon-containing gas through the porous material at
600-650° C., then the treatment with the solution of the salt of
the active metal selected from a group consisting of Co, Fe or Ru is
repeated until the metal content of 10-45% by weight based on the total
weight of the catalyst has been achieved, followed by drying and
calcinating.

[0045] In one preferred embodiment of the invention the active component
is a metal selected from Co, Fe or Ru and the metal content is 10-45% by
weight based on the total weight of the catalyst.

[0046] In one preferred embodiment of the invention the oxide component is
selected from oxides of aluminium, silicon, titanium, zirconium,
magnesium or lanthanum, zeolites, mixed oxides and/or mixtures thereof.

[0047] In one preferred embodiment of the invention the carbon nanotube
content is 10-35% by weight based on the total weight of the catalyst.

[0048] In one preferred embodiment of the invention further the support is
impregnated with a solution of a promoter salt, moreover metals of II-IV
and/or VI-VIII groups of the Mendeleev's Periodic Table of the Elements
and/or oxides are used as the promoters and the promoter content is
0.1-5% by weight based on the total weight of the catalyst.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS

[0049] Numerous experimental studies of the inventors demonstrate that in
contrast to the known use of the nanotubes (Chin Y. H. et.al.,
Preparation of a novel structured catalyst based on aligned carbon
nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor,
Catalysis Today, v. 110, pp. 47-52, 2005) the procedures of the present
method gives possibility to prepare an ordered arrangement of the
nanotubes fixed on the walls of the transport pores of the catalyst
pellets instead the compacted, oriented in one direction nanotube array
with the active centers on the free ends of the nanotubes on the
metalloceramic support. The active centers in the present catalyst are
positioned close to the fixed end of the nanotubes that is effective for
providing heat- and mass-transfer in the process of hydrocarbon
production from CO and H2. The claimed catalyst and the preparation
method thereof make possible to form the catalytic bed for the process of
hydrocarbon production from CO and H2 in accordance with the current
requirements, i.e. providing high concentration of a catalytically active
component in the reaction volume; the small size of the catalyst
particles less than 50 μm, high heat conductivity of the catalyst bed,
the extended surface of the gas-liquid interphase and regimen of the gas
convection current close to plug flow.

[0050] In accordance with the present invention a catalyst for synthesis
of hydrocarbons from CO and H2 is provided. The catalyst comprises a
metal selected from the Group VIII of the Mendeleev's Periodic Table of
the Elements as an active component and a porous support with an oxide
component and carbon component. The carbon component is carbon nanotubes
(CNT) which are grafted (fixed) into the pore walls of the support.

[0051] The graft of the carbon nanotubes onto the pore walls of the oxide
component takes place during their growth (deposition) by CVD on the
particles of the metal of the active component, selected from Group VIII
of the Mendeleev's Periodic Table of the Elements, e.g., Co, Fe or Ru.
The metal particles are loaded onto the porous oxide support in the
process of the impregnation with a solution of the metal salt.

[0052] The oxide component of the support is a porous material consisting
of oxides of aluminium, silicon, titanium, zirconium, magnesium or
lanthanum, zeolites, mixed oxides and/or mixtures thereof, the porous
material content is 45-80% by weight based on the total weight of the
catalyst. The pores in the oxide component make possible to fix the
carbon nanotubes on the metal particles in such way to graft the carbon
nanotubes into the pore walls, moreover the pore size is at least 10 nm,
these facts provide the efficient product evacuation from the active
centers. The oxide component can have the different form, e.g. pellets,
balls; their size may be changed from 1 to 5 mm.

[0053] The oxide component content less than 45% based on the total weight
of the catalyst is undesirable because of the significant lowering in the
catalyst selectivity of C5 hydrocarbons; the component content more
than 80% decreases considerably the catalyst activity in the hydrocarbon
production.

[0054] The active component (Co, Fe or Ru) content is 10-45% by weight
based on the total weight of the catalyst. The metal content less than
10% and more than 45% is unreasonable.

[0055] The carbon nanotube content is 10-35% by weight based on the total
weight of the catalyst. The content less than 10% does not tale effect
and more than 45% decreases the catalyst activity in the hydrocarbon
production.

[0056] The catalyst further comprises promoters, moreover the elements of
II-IV and/or VI-VIII groups of the Mendeleev's Periodic Table of the
Elements are used as the promoters and the promoter content is 0.1-5% by
weight based on the total weight of the catalyst. The promoters are
introduced into the catalyst by impregnation with a solution of the metal
salt.

[0057] The present invention also relates to a method for preparing the
claimed catalyst for synthesis of hydrocarbons from CO and H2
comprising: the active metal selected from the Group VIII of the
Mendeleev's Periodic Table of the Elements, such as Co, Fe or Ru, is
applied onto the oxide component by impregnation with an aqueous solution
of the metal salt. Then the sample is dried, calcinated and treated in
hydrogen stream to obtain the porous material. The carbon nanotubes in an
amount of 10-35% by weight based on the total weight of the catalyst are
grafted by CVD from the carbon-containing gas at 600-650° C. The
porous material with grafted CNT is impregnated again with the solution
of the salt of the active metal selected from a group consisting of Co,
Fe or Ru until the metal content of 10-45% by weight based on the total
weight of the catalyst has been achieved, followed by drying and
calcinating.

[0058] The porous support with the CNT grafted into the pore walls is
impregnated with a solution of a promoter salt. Metals of II-IV and/or
VI-VIII groups of the Mendeleev's Periodic Table of the Elements and/or
oxides are used as the promoters and the promoter content is 0.1-5% by
weight based on the total weight of the catalyst.

[0059] It was established that use of the present catalyst in the
hydrocarbon production enhanced the stability to overheating even at high
load of synthesis gas. Simultaneously the main product productivity
increases.

[0060] The carbon nanotubes are grafted into the pore walls of the support
by the active metal particles during CVD and oriented towards the gas
flow. These facts improve the catalyst properties, e.g. they provide an
improved mass- and heat transfer.

[0061] The present catalyst, comprising CNT, may be used in the
Fischer-Tropsch reaction, oxidation reaction CO, steam reforming,
hydrogenation of alkenes (among them selective alkadienes and alkynes
into olefins), n-butane dehydrogenation, and CO hydrogenation.

[0062] In accordance with the present method the formation of the catalyst
containing CNT requires the previous preparation of the porous support.
For this purpose the active metal selected from the Group VIII of the
Mendeleev's Periodic Table of the Elements, such as Co, Fe or Ru, is
introduced onto the oxide component by impregnation with an aqueous
solution of the metal salt, followed by drying and calcinating and
treatment in hydrogen stream at 500° C. during 2 hours. The carbon
nanotubes in an amount of 10-35% by weight based on the total weight of
the catalyst are deposited and grafted by CVD on the active metal
particles in the pore walls of the oxide component.

[0063] The CVD is carried out with the carbon containing gas. Methane,
acetylene, carbon monoxide doped with hydrogen and/or inert gases (argon,
helium) is used as carbon containing gas. The porous material with the
active metal particles is put in the vertical flow reactor and heated to
the reaction temperature. The carbon-containing gas is continuously
supplied into the reactor and the gas products are evacuated. The reactor
is a quartz tube of 30 mm diameter and 400 mm length). The quartz tube is
blown off with the inert gas for air discharge. The porous material is
previously reduced. The synthesis is performed at a pressure 0.01-1 MPa
and a temperature 500-1100° C. during 30-240 min. The porous
material is allowed to cool down to room temperature and is discharged
from the reactor.

[0064] The active metal is applied by impregnation with an aqueous
solution of the salt (nitrate, acetate, formate, acetylactonate etc.) of
Co, Fe or Ru. Depending on the amount of the active metal the
impregnation can be multistage, i.e. single-stage, two-stage etc. Each
stage involves drying in water bath, followed by drying and/or
calcinating in the inert gas flow at temperature of 100-1000° C.
during 60-600 min. If necessary the procedure is repeated with promoters.

[0065] Before CNT deposition and graft into the pore walls of the porous
system of the oxide component, the porous material is activated by
reduction in the stream of hydrogen (gas hour space rate 1000-5000 1/h)
at a temperature in the range from 500 to 800° C. during 60-180
min.

[0066] Before carrying out the synthesis of hydrocarbons, a sample of the
catalyst is activated by reduction in the stream of hydrogen (gas hour
space rate 1000-5000 1/h) at a temperature in the range from 300 to
600° C. during 60-300 min.

[0067] Synthesis of hydrocarbons from CO:H2 is carried out in a
tubular reactor with a fixed bed of the claimed catalyst under a pressure
in the range from 0.1 to 4 MPa and a temperature in the range from 150 to
300° C. The molar ratio of CO:H2 in synthesis gas is in the
range from 1:1 to 1:3.

[0068] To further illustrate various illustrative embodiments of the
present invention the following examples are provided.

[0071] 0.05 g Co from an aqueous solution of cobalt nitrate is applied on
1 g oxide component SiO2 by wet impregnation, then dried and
calcined. The obtained material is treated in hydrogen stream at
temperature of 500° C. during 2 hours, placed in the reactor of 30
mm diameter, heated until temperature of 650° C. in hydrogen
stream and then the methane-hydrogen mixture with ratio CH4:H2
as 2:1 and feed rate of 40:20 ml/min is introduced into the reactor. The
deposited CNT are fixed on cobalt particles of the porous system walls of
the support. Unreacted methane and hydrogen are taken away from the
reactor through a trap. Synthesis time is 30 min. On completing the
reactor is allowed to cool down to room temperature in a flow of hydrogen
and the obtained material is discharged from the reactor. The material is
the porous support containing the oxide component and carbon nanotubes of
cone and cylinder structure with a diameter of 8-70 nm.

[0072] 2. Preparation of the Sample of the Catalyst.

[0073] 0.05 g Co from an aqueous solution of cobalt nitrate is applied on
the support with the CNTs grafted in the pores, and then the sample is
dried and calcined.

[0074] Prior to use in a Fischer-Tropsch reaction the catalyst sample is
activated with hydrogen stream (gas hour space rate 3000 1/h) at
400° C. during 1 hour. Synthesis of hydrocarbons is carried out in
a tubular reactor with a fixed bed of the catalyst at 2 MPa and
160-240° C., using the molar ratio of CO:H2 in synthesis gas
as 1:2 (gas hour space rate 3000 1/h).

[0077] Cobalt is applied on 1 g oxide component Zeolite HY by wet
impregnation, the material is treated, as described in EXAMPLE 1. The
obtained material is placed in the reactor of 30 mm diameter, heated
until temperature of 500° C. in argon stream and then the
acetylene-argon mixture with ratio C2H2:Ar as 1:7 and feed rate
of 12:93 ml/min is introduced into the reactor. The deposited CNT are
fixed on cobalt particles of the porous system walls of the support.
Unreacted acetylene and argon are taken away from the reactor through a
trap. Synthesis time is 120 min. On completing the reactor is allowed to
cool down to room temperature in a flow of argon and the obtained
material is discharged from the reactor. The material is the porous
support containing the oxide component and carbon nanotubes of cone and
cylinder structure with a diameter of 8-60 nm.

[0078] 2. Preparation of the Sample of the Catalyst.

[0079] 0.20 g Co from an aqueous solution of cobalt nitrate is applied on
the support with the CNTs grafted in the pores, and then the sample is
dried and calcined.

[0080] Prior to use in a Fischer-Tropsch reaction the catalyst sample is
activated with hydrogen stream (gas hour space rate 3000 1/h) at
450° C. during 1 hour. Synthesis of hydrocarbons is carried out in
a tubular reactor with a fixed bed of the catalyst at 2 MPa and
160-240° C., using the molar ratio of CO:H2 in synthesis gas
as 1:2 (gas hour space rate 3000 1/h).

[0083] Cobalt is applied on 1 g oxide component MgO by wet impregnation,
the material is treated, as described in EXAMPLE 1. The obtained material
is placed in the reactor of 30 mm diameter, heated until temperature of
650° C. in hydrogen stream and then the methane-hydrogen mixture
with ratio CH4:H2 as 2:1 and feed rate of 80:40 ml/min is
introduced into the reactor. The deposited CNT are fixed on cobalt
particles of the porous system walls of the support. Unreacted methane
and hydrogen are taken away from the reactor through a trap. Synthesis
time is 180 min. On completing the reactor is allowed to cool down to
room temperature in a flow of hydrogen and the obtained material is
discharged from the reactor. The material is the porous support
containing the oxide component and carbon nanotubes of cone and cylinder
structure with a diameter of 8-50 nm.

[0084] 2. Preparation of the Sample of the Catalyst.

[0085] 0.40 g Co from an aqueous solution of cobalt nitrate is applied on
the support with the CNTs grafted in the pores by impregnation, and then
the sample is dried and calcined.

[0086] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

Example 4

[0087] A sample of catalyst comprising 25% Fe/(65% La2O3+10%
CNT) is prepared as follows. 1. Preparation of Catalyst Support with CNT.

[0088] 0.05 g Fe (III) is applied on 1 g oxide component La2O3
by wet impregnation, the material is treated, as described in EXAMPLE 1.
The obtained material is placed in the reactor of 30 mm diameter, heated
until temperature of 600° C. in nitrogen-hydrogen mixture stream,
N2:H2 ratio=2:1 and then the mixture of acetylene, nitrogen and
hydrogen with volume ratio C2H2:N2:H2 as 1:7:4 and
feed rate of 12:93:45 ml/min is introduced into the reactor. The
deposited CNT are fixed on cobalt particles of the porous system walls of
the support. Unreacted acetylene, nitrogen and hydrogen are taken away
from the reactor through a trap. Synthesis time is 180 min. On completing
the reactor is allowed to cool down to room temperature in a flow of
hydrogen and the obtained material is discharged from the reactor. The
material is the porous support containing the oxide component and carbon
nanotubes of cone and cylinder structure with a diameter of 8-60 nm.

[0089] 2. Preparation of the Sample of the Catalyst.

[0090] 0.20 g Fe from an aqueous solution of ferric nitrate is applied on
the support with the CNTs grafted in the pores by impregnation, and then
the sample is dried and calcined.

[0091] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0094] 0.05 g Ni from an aqueous solution of nickel nitrate is applied on
1 g oxide component TiO2 by wet impregnation, the material is
treated, as described in EXAMPLE 1. The obtained material is placed in
the reactor of 30 mm diameter, heated until temperature of 700° C.
in hydrogen stream and then the mixture of acetylene, nitrogen and
hydrogen with volume ratio C2H2:N2:H2 as 1:7:4 and
feed rate of 12:93:45 ml/min is introduced into the reactor. The
deposited CNT are fixed on cobalt particles of the porous system walls of
the support. Unreacted acetylene, nitrogen and hydrogen are taken away
from the reactor through a trap. Synthesis time is 120 min. On completing
the reactor is allowed to cool down to room temperature in a flow of
hydrogen and the obtained material is discharged from the reactor. The
material is the porous support containing the oxide component and carbon
nanotubes of cone and cylinder structure with a diameter of 5-10 nm.

[0095] 2. Preparation of the Sample of the Catalyst.

[0096] 0.05 g Ni from an aqueous solution of nickel nitrate is applied on
the support with the CNTs grafted in the pores by impregnation, and then
the sample is dried and calcined.

[0097] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

Example 6

[0098] A sample of catalyst comprising 20% Ru/(70% Al2O3+10%
CNT) is prepared as follows. 1. Preparation of Catalyst Support with CNT.

[0099] 0.05 g Ru is applied on 1 g oxide component Al2O3 by wet
impregnation, the material is treated, as described in EXAMPLE 1. The
obtained material is placed in the reactor of 30 mm diameter, heated
until temperature of 650° C. in hydrogen stream and then the
methane-hydrogen mixture with ratio CH4:H2 as 2:1 and feed rate
of 110:55 ml/min is introduced into the reactor. The deposited CNT are
fixed on cobalt particles of the porous system walls of the support.
Unreacted methane and hydrogen are taken away from the reactor through a
trap. Synthesis time is 120 min. On completing the reactor is allowed to
cool down to room temperature in a flow of hydrogen and the obtained
material is discharged from the reactor. The material is the porous
support containing the oxide component and carbon nanotubes of cone and
cylinder structure with a diameter of 8-70 nm.

[0100] 2. Preparation of the Sample of the Catalyst.

[0101] 0.15 g Ru from an aqueous solution of ruthenium nitrate is applied
on the support with the CNTs grafted in the pores by impregnation, and
then the sample is dried and calcined.

[0102] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

Example 7

[0103] A sample of catalyst comprising 40% Co/(50% ZrO2+10% CNT) is
prepared as follows. 1. Preparation of Catalyst Support with CNT.

[0104] 0.05 g Co is applied on 1 g oxide component ZrO2 by wet
impregnation, the material is treated, as described in EXAMPLE 1. The
obtained material is placed in the reactor of 30 mm diameter, heated
until temperature of 650° C. in hydrogen stream and then the
methane-hydrogen mixture with ratio CH4:H2 as 2:1 and feed rate
of 80:40 ml/min is introduced into the reactor. The deposited CNT are
fixed on cobalt particles of the porous system walls of the support.
Unreacted methane and hydrogen are taken away from the reactor through a
trap. Synthesis time is 120 min. On completing the reactor is allowed to
cool down to room temperature in a flow of hydrogen and the obtained
material is discharged from the reactor. The material is the porous
support containing the oxide component and carbon nanotubes of cone and
cylinder structure with a diameter of 8-60 nm.

[0105] 2. Preparation of the Sample of the Catalyst.

[0106] 0.35 g Co from an aqueous solution of cobalt nitrate is applied on
the support with the CNTs grafted in the pores by impregnation, and then
the sample is dried and calcined.

[0107] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0110] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 10-80 nm.

[0111] 2. Preparation of the Sample of the Catalyst.

[0112] 0.03 g Ba and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0113] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0116] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 8-70 nm.

[0117] 2. Preparation of the Sample of the Catalyst.

[0118] 0.015 g Al and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0119] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0122] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 8-90 nm.

[0123] 2. Preparation of the Sample of the Catalyst.

[0124] 0.03 g Zr and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0125] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0128] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 10-80 nm.

[0129] 2. Preparation of the Sample of the Catalyst.

[0130] 0.03 g Cr and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0131] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0134] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 8-60 nm.

[0135] 2. Preparation of the Sample of the Catalyst.

[0136] 0.001 g Re and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0137] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0140] The porous support with the oxide component and carbon nanotubes is
prepared as described in EXAMPLE 2. The carbon nanotubes have the cone
and cylinder structure with a diameter of 8-70 nm.

[0141] 2. Preparation of the Sample of the Catalyst.

[0142] 0.005 g Fe and 0.2 g Co from the aqueous solutions of the
appropriate salts are applied on the support with the CNTs grafted in the
pores by impregnation, and then the sample is dried and calcined.

[0143] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

Example 14

Comparison with the Known Catalyst of the Fischer-Tropsch Process 20%
Co/(80% Zeolite)

[0144] A sample of catalyst comprising 20% Co/(80% Zeolite) is prepared as
follows. 1. Preparation of Catalyst Support

[0145] The granular zeolite HB is used as support. 2. Preparation of the
Sample of the Catalyst.

[0146] Cobalt is applied as described in EXAMPLE 1.

[0147] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

Example 15

Comparison with the Known Catalyst of the Fischer-Tropsch Process 20%
Co/CNT according to EP1782885

[0148] A sample of catalyst comprising 20% Co/CNT is prepared as follows.

[0149] 1. Preparation of Catalyst Support

[0150] The carbon nanotubes are grown by CVD from ethylene according to
the method disclosed by Chin Y. H. et.al., in Catalysis Today, v. 110,
pp. 47-52, 2005. The support is a flaky black powder with the bulk
density of 0.4 g/cm3.

[0151] 2. Preparation of the Sample of the Catalyst.

[0152] Cobalt is applied as described in EXAMPLE 1.

[0153] The activation of the catalyst and the synthesis of hydrocarbons
are performed as described in EXAMPLE 1.

[0154] The results of the synthesis of hydrocarbons from CO and H2
with samples of the catalysts of the composition according to Examples
1-15 are shown in the TABLE 1 below.

[0155] The results shown in Table 1 demonstrate that if compare the
catalyst according to the present invention containing the carbon
nanotubes grafted to pore walls of the support and the catalyst of
Example 14 without the carbon nanotubes, then CO conversion and the
productivity for C5 and higher hydrocarbons increases and CH4
selectivity drops. The catalyst of Example 15 has low activity when the
synthesis gas hour space rate is 3000 1/h.

[0156] Therefore the catalyst for synthesis of hydrocarbons according to
the present invention is an effective, selective catalyst of new type,
such catalyst is stable to overheating, reliable, with improved heat- and
mass-transfer in the catalyst pellet and in the catalyst bed as a whole,
low-cost along with high activity. The preparation method of the catalyst
is simple and safe.